Donna Tisdale’s boundless backyard may not be God’s greenest acre, but look at it.

Stand along a gravel road on her 310-acre Boulevard spread — the Morning Star Ranch, she and her husband call it — and turn east and you can see the In-Ko-Pah and Jacumba mountains, chocolate and orange in the late-afternoon sun. To the north sits McCain Valley and a row of giant wind turbines. To the south, a short hike away, are the knobby peaks of Baja California. And to the west, some 50 miles from the ranch, is metropolitan San Diego. You can’t see a lick of it from this spot and that’s probably just as well.

In San Diego, Tisdale said, “it’s hard to find even a square inch where you can retreat from the noise and the activities of city life.”

For close to a quarter-century, the dogged activist has been standing up to big business and big-city ideas in the name of preserving the San Diego County backcountry and its rural ways.

She’s sued San Diego Gas & Electric over Sunrise Powerlink, the mammoth transmission line that will cut through East County. She’s challenged telecommunications companies over the placement of cell towers. She’s tangled with energy corporations over plans for industrial-scale wind and solar farms.

Tisdale, who has chaired Boulevard’s community planning board since 1990, believes the projects will spoil a landscape still studded with giant oaks, more dirt roads than asphalt and where you can see the Milky Way most nights.

“I never get tired of looking at the views” she said Thursday. “To me, it’s soothing to the soul.”

For this she gets dismissed by some as a chronic complainer and an impediment to progress.

“A lot of people don’t like me,” she said.

Others see someone with gumption, a sort of Erin Brockovich, without the blond locks and toothy, Hollywood looks.

Tisdale, a 59-year-old grandmother, has drawn accolades from organizations over the years. In June, she won the 2011 conservation activist award from the San Diego chapter of the Sierra Club.

“I’d describe Donna as a backcountry warrior,” said Supervisor Dianne Jacob, who represents East County. “At her core, I think she loves her community the way a mother lion loves her cub.”

Tisdale would like to say that all her recent hard work has paid off.

The hard-hats and helicopters crowding her community suggest otherwise.

Construction of SDG&E’s Powerlink is in full swing, despite on-going legal attempts by Tisdale, Jacob and a community coalition to stop it. Several sprawling wind and solar projects are expected to get under way soon, once the federal government gives the green light.

Yet Tisdale keeps going.

“I don’t have an off switch,” she said.

Ed Tisdale, her husband of 33 years and a retired building contractor, says there’s no use trying to get her to slow down. She’s going to do what she needs to do.

So this is what she keeps doing: Pressing government agencies and private industry officials on a range of rural issues, reminding them that someone is watching them and that that someone has done her homework.